The recent incidents of building collapse especially in Freetown has expectedly, generated a lot of concerns and commentaries in both the print and electronic media respectively. The blunt truth is that the journey to the collapse of buildings began long ago. The only difference being that the quality of local builders of the 70’s and 80’s was by far higher than the free-for-all field that the construction sector has today degenerated to.
At independence, the Kissy Trade School, Freetown Technical Institute, the Public Works Department Training School and a number of other technical colleges in the provinces produced top notch construction artisans and tradesmen across the sub-fields of electrical installation, carpentry, welding, roofing, steel bending, tiling, painting, plumbing etc. Some of these highly skilled cadres trained other younger hands who carried on with the expertise, diligence and commitment of their trainers. The buildings erected by this generation of artisans are the properly constructed old buildings that still stand out in different locations of Freetown today. Things took a different turn when the 1991-2002 civil war thoroughly pillaged these once respected training facilities and resulted in the death or relocation of a majority their very talented teaching staff.
For most buildings in Freetown and especially those located around seaside and ocean fronts, the rate of deterioration is faster due to concomitant damage from saline moisture which gradually ruins steel components such as railings, window guard bars and the steel elements of electro-mechanical equipment such as airconditioners, water heaters, refrigerators etc via corrosion. This also, usually manifests as spalling when under a situation of insufficient concrete cover, embedded re-bars in concrete swell in size due to salty moisture and end up detaching from the concrete. This becomes visible as spalling on structural slabs, beams, columns and soffits of reinforced concrete stairs. Buildings located near the sea also have a lot of exposure to substantial wind-loads especially for multi-storey structures. A couple of them have had their roofs blown-off by intense winds.
Some of the reasons why we are witnessing these recent spate of building failures in Freetown are as follows: –
Substandard Construction: The quality of most of the buildings erected lately leaves much to be desired. We have seen foundation depths of 600mm (2feet) for a 3-floor building with insufficient and/or wrongly placed steel reinforcement bars. We have also seen eccentrically placed columns which by their construction, are unable to efficiently transmit loads (both of the building structure itself and live loads imposed by occupants and all the stuff in the buildings) to the ground below its foundations.
Deviation from Designs, Approved Work Methods, specifications and Codes of Practice: Evidence abound that most of our buildings do not align with their original designs. We have seen single family maisonettes that were spatially altered midstream in construction, by their owners to blocks of flats. Ideally, they should have submitted the modified drawings for a new Building Permit that reflects the radically and unilaterally altered designs of the original development.
Any change to the building design half-way could have critical implications on foundations and the original design/sizes of reinforced concrete columns, beams and slabs. A lot of developers hardly revisit their drawings and instead resort to ordering their contractors on site to extend say, the surface areas of slabs and create more rooms. This is very common in Freetown and has a potential to trigger a collapse if the after-thought extensions result in additional loads that were not factored when the foundation was constructed months earlier.
Regulatory Deficits: Ideally, for any building to be erected, it should have earned a building permit issued by the Ministry of Lands, Housing & Country Planning (MLHCP). The building plans and drawings submitted ought to have been designed by the right caliber of professionals such as registered architects and engineers. Any intended or un-intended breaches of this key requirement which translates into sub-standard construction could result in collapse.
We have seen influential one-man developers who proceed to erect their buildings without obtaining the statutorily required building permits. These abound around the large expanses of the eye-catching hill slopes that partially encircle the City of Freetown. Any building that is erected without a permit should be suspect from the outset and should ideally be brought down in order to save lives and deter other unruly developers from following suit.
The entire Ministry of Lands, Housing and Country Planning currently has less than 40 Building Inspectors to monitor the over 7,000 houses currently under construction country-wide. Literally, this pans out as 1 building Inspector for 175 building sites. This is without doubt and from the outset, a “mission impossible” scenario. The Local Government Act of 2004 prescribes the devolution of the function of issuance of building permits to the councils. It should be appreciated that any cadre of building inspectors to be employed under any of these structures whatsoever, should have the proper orientation, requisite training and the tools to equip them for the efficient performance of their duties.
Sub-standard Materials: Sadly, Sierra Leone is one of the destinations for sub-standard building materials. Recently, my office procured from a local builders’ merchant some sizes of steel reinforcement bars (rods) for assessment. Our finding was mind boggling: For 6mm iron rods, the actual diameter we got from the vernier caliper was 4.5mm, the ubiquitous 12mm (half-inch) rod manifested as 10.5mm, 16mm (5/8”) rods turned out to be 14mm. Beside the diameters, the standard lengths of 12 meters (about 39 feet) often arrive Freetown as 10.5m (34.5 feet). Another issue with the imported rods on construction sites is the excessive carbon content in some batches which makes them brittle. This could have very grave implications especially when they are placed to perform a tensile function in which case they would easily crack and trigger shear and likely failure of that structural element.
Developers who buy these deficient and disguised rods that are not what they are named in invoices, risk the prospect of structural failure if they don’t have consultants to advise them to either buy more than the designed quantities or procure the next larger diameter as a way of compensating for the reduced volume of the rods.
The Sierra Leone Standards Bureau whose responsibility is to regulate the quality of materials manufactured, sold or imported into Sierra Leone is unable to adequately perform its duties because it is currently beset with a number of drawbacks largely bordering on paucity of resources. Given adequate funding and additional investment on modern quality certification equipment, reagents and vehicles to enforce its mandate, the Standards Bureau will perform a whole lot better than we are seeing today.
Uncontrolled Reclamation of Swamp Lands: One largely ignored act of people dwelling around the various creeks and shorelines of the Rokel river in Freetown is the informal reclamation of shores and once thriving creeks. This is prevalent on the creek-side of Sir Samuel Lewis Road in Aberdeen otherwise known as the Aberdeen creek, Crab Town, Thompson’s Bay, Susan’s Bay, Marbaella, Cline Bay, the Kaningo area, Portee wharf, Kroo Bay, Murray Town Wharf, Sawpit, Cockle Bay to name a few.
In these areas, once thriving marine habitats are routinely mowed-down and backfilled with garbage, an assortment of debris and laterite, in desperate efforts to reclaim land for construction of houses. The resultant destruction of existing ecosystems and in some cases, biodiversity remains incalculable as pristine shorelines and un-spoilt creek-fronts are recklessly violated and exploited for low quality construction. Most of the structures put up in these places are neither backed by architectural designs nor permits.
Whole communities have come to permanently reside in these sordid fringes of the Freetown metropolis. Majority of these informal settlements are flooded and therefore unlivable during the perennial heavy rains that often brings Freetown to a standstill. Many of them have no access to “GUMA Water”, roads or drainages. Over 80% of electricity connections in these communities are often illegal. The resultant buildings are in most cases, not having the right quality of foundations for such exacting ground conditions. Most of the houses and shanties built in these places do regularly experience collapse and fire outbreaks because of over-crowding and haphazard connections to the mains electricity grid.
Deficient Design: Buildings do collapse too if the envisioned load scenarios, soil conditions, assumed occupancies and final use of the building were not properly recognized and taken cognizance of during the design stages. This is why geotechnical investigations will usually be of utmost relevance to direct the foundation designs from an informed position. In a country where over 80% of buildings are designed by quacks, unqualified and unregistered players, building collapses will continue to be a recurring decimal. This is no doubt, a grim prospect, considering that precious lives and properties will continue to be lost.
Quality of Supervision: It is one thing to have a beautiful and/or functional design, but another to put in place the framework to ensure strict adherence by contractors to the architectural designs, structural engineering designs, services engineering designs, specifications, codes of practice, and statutory regulations. This is where the supervision or project management role becomes unavoidably germane to the quality of the construction outcomes.
Poor Quality Foundations
The entire weight of a building and its contents rest on its foundation. The foundation in turn distribute its dead and imposed loads safely to the ground beneath that has the right bearing capacity. The choice of the foundation type basically depends on the overall load/weight of the building, type of terrain and quality of the soil. It was reported that the recently collapsed building in Kissy was founded on an old refuse dump and that pad and strip foundations were used in its construction. We honestly find this choice to be preposterous if is in deed true.
Refuse dumps are generally very unsafe to construct upon because they largely consist of decaying matter and garbage. It is advised in such circumstances, to either drive piles through it to found the building on a stable strata below that possess the right bearing capacity to handle the cumulative loads of the building in question. Another option could be to painstakingly rid the location of all its trash and biodegradable materials until a stable ground below is located. After then, a fitting foundation system will be constructed to safely handle the cumulative loads of the building. Given the benefit of a proper soil test results, the most appropriate foundation system can be smartly arrived at.
The Swampy/coastal neighbourhoods of Susans Bay, Aberdeen Creek, Thompson Bay, Marbaella, Portee Wharf, Murray Town Creek, Crab Town etc all require carefully thought out foundation systems due to the often muddy nature of the soils here and the preponderance of ground moisture as well as, their propensity to get flooded during the thick of the rainy season. The likely foundation choice in these areas will be between piles or raft as determined by geotechnical results.
Lack of a Maintenance Culture: Buildings also do eventually collapse when issues arise that need immediate remedial actions but instead left un-attended. Such neglect usually results in further incremental deterioration. Most buildings headed for structural collapse start by manifesting the tell tale signs of cracks on columns and beams, signs of buckling of columns, advanced spalling on the soffits of staircases, reinforced concrete floor slabs and the underside of key structural beams. So long as these symptoms are continuously overlooked or neglected, they will get worse with time and eventually fail.
Excessive Loading: We have two types of basic loads in a building. Simply put, these are the dead load which refers to the load of the incorporated building elements (such as beams, columns, slabs, roof etc), whilst the live loads are the imposed ones (such as by the occupants, furniture, appliances like washing machines, refrigerators etc). Ideally, the structure of buildings are meticulously designed by structural engineers by taking cognizance of a certain range of load factors as well as, providing for a reasonable factor of safety in compliance with the pertinent professional or national codes.
Freetown has a lot of buildings in the city centre that were designed as residential occupancies but have floors, (in some instances suspended slabs) that are brazenly being currently used for the warehousing of merchandise and building materials. Preliminary reports on the recent Kissy collapse reveal that additional floor slabs were constructed on a foundation earlier intended for a 3-floor building. We were also informed that some of the floors were being used to store building materials. Every foundation is designed for a specific amount of loading. Once this is exceeded, the result is the outright or gradual failure of its structural elements.
The National Building Code & Current Regulatory structure: Investment in buildings often represent a substantial financial outlay for both individuals and institutions. This is why such initiatives must be prudently conceived, carefully planned and pursued in accordance with a set of regulations and processes for its entire value chain, till realization. First stage is contracting the services of an Architect to prepare the architectural drawings of the building in sync with the client’s dreams, then the Structural and Electro-Mechanical Engineering drawings will follow and usually, the cost breakdowns/Bills of Quantities by the Quantity Surveyor. The drawings are then signed and sealed by the professionals involved and forwarded by the Architect or Architectural firm to the Ministry of Lands, Housing and Country Planning (MLHCP) for building permit.
Ideally, the MLHCP has the responsibility to ensure that the drawings submitted to them have been duly prepared and signed by registered Architects for all Architectural drawings and registered Engineers for all Engineering Drawings for buildings of one suspended slab and more {according to the 2021 Sierra Leone Institute of Architects’ (SLIA) crafted Building Code}. After proper scrutiny of these documents and due-diligence including an inspection of the intended site, and all requisite conditions met, a permit is issued. Beyond the issuance of the permit, the Ministry has in its employment, building inspectors whose role is to ensure that the construction activity is backed by a permit and also that, the approved drawings are strictly being conformed with on the site.
The MLHCP has striven to deliver services to the public notwithstanding, the enormous responsibilities they have to discharge regularly. The ministry needs more trained personnel to adequately service the public. They have for the longest times remained under-staffed and under-resourced to conduct the delivery of their statutory mandate. In the view of the public, a few operatives of the ministry have been seen as not living up to the expectations of their roles in their lines of duty. A school of thought in fact, sees the MLHCP as also largely contributing to the malaise of this sector. We believe that this perception can be improved through regular engagements with the public and internal re-orientation of its personnel. The advent of the National Lands Commission is shortly, expected to result in a paradigm shift in the business of land administration in Sierra Leone.
All in all, there’s still a lot to be done with regards to building regulations. Sierra Leone is as at today, one of the very few jurisdictions globally that still doesn’t have an operational national building code. In 2019, during a courtesy call on the President, His Excellency (Dr.) Julius Maada Bio, he tasked the SLIA to work in unison to develop a National Building Code that will build upon a draft code that had been previously articulated by the Ministry of Works and Public Assets and the Engineers.
With a sense of mission and patriotism, the SLIA worked assiduously for over 2 years and formally submitted an updated Draft of the new National Building Code to H.E the President, in 2021. This ongoing menace of building collapse was recognized from the outset and thoroughly dealt with in this building code, by virtue of the several preventive steps encapsulated in it. Once this very important document is hopefully, passed into law, it will positively impact the built environment of the country and finally put in check, these recent threats of building failures in Freetown and the regions of Sierra Leone.
Arc. Abel. T. ONOMAKE fnia, mslia
Director at the Consulting Firm of
IDEAS Ltd. Sierra Leone.